God Bless America Cake (aka Cajun #Cake)

I made this cake for my Dad's Birthday this weekend, German Chocolate cake is his favorite, but I wanted to mix it up a little bit. The cake was super moist and very delicious. However the icing wouldn't thicken for me. Ended up more like a "Poke Cake" but still tasted lovely. My aunt suggested to me to add 3 egg yolks to the icing recipe to thicken it up.